In this last part of the "What is a Left-hander" section, I'll explore who we think of as being left-handed, and give my ideas as to what it all means.
Left-handed proportion of the population
As of 1980, there were:
- approximately 35 million left-handed people in the United States (about 15%).
- an estimated 150 to 200 million left-handed people in the world.
- more male than female left-handers.
- 11-13% of the general population considered left-handed.
It's actually not an easy thing to determine.Most of the time, we consider someone who writes with the left hand to be left-handed, and those using the right to be right-handed.
Yet there are some people who write with the right hand, and are actually left-handed, due to either being switched when learning to write, or injury forcing use of the right hand. These people may be able to do other activities left-handed, such as throwing, eating, brushing teeth, you name it, and yet not think of themselves as left-handed. Determining how strongly an individual uses one hand or the other can be determined by questioning, although there is no uniformly agreed-upon method used for this. Most people "just know" they are left-handed, which is not very useful for scientific research purposes.
There are also many people who do certain activities with one hand, and different actions with the other. Most people that we consider "left-handed" could actually more accurately be called "mixed-handed," or even "non-right-handed." They may do fine motor activities with the left hand, and gross motor activities with the right, or some other combination that is neither totally right nor totally left oriented. Yet, people who are right-handed generally do everything with that hand. Why is it this way?
In my Webliography, there are links to some simple tests online which can give a general idea of where an individual falls on the spectrum of left to right-handedness. And then there are the considerations of which ear, eye, and foot we favor. Some people are "cross-lateral" in this respect, perhaps writing with the right hand, but kicking with the left foot, or favoring the opposite eye to sight through a camera lens.
So, what is a left-hander?The general conclusions here are that we still don't know!
- Although some left-handedness occurs due to brain injury, it is extreme to think that it causes many or all left-handers.
- Figuring out the puzzle of what causes left-handedness is still a work in progress.
- Neuroscientists have been trying to answer the question for many years, and still have no definitive answer.
- There have been many studies done, and the results are sometimes promising, but not conclusive, and often as not there will be another study to challenge the first's findings.
It appears it will be some time before we have any definitive scientific conclusions!
Also, as we've seen on this page, we have yet to define what qualifies one as a left-hander. How can we measure handedness, and what tests will be used to do so? Perhaps this can fall under the medical umbrella, and become part of a physical examination. If we can make an effort to learn more about who left-handers are, we might be better able to accommodate them.
